[Fix] File format unsupported or invalid for DMG files
There are few ways to convert MAC DMG image to ISO but none work for me. It fails with "The file format is invalid or unsupported" or "Can'nt find the file or file isn't CD image file" error. "The file format is invalid or unsupported"Is this kind of message telling you that file are corrupted? No.. DMG file is not corrupted. You can convert DMG to ISO via MAC OS x. Check step by step Guide for converting DMG to ISO.
